Now there's one thing you are forgetting with this case, and it is the final word, the grease that runs the gears of companies and nations alike; money. Aerospace companies are under pressure to develop features quickly for the benefit of the market, just like all competitive business. There are 2 important factors determining this; time-to-market and cost-of-production. There are some systems that need to be ensured to be reliable, like flight OM and others that are not so critical like entertainment systems. A company can save a truckload of money for each physical component that is not included in the plane; it generates savings in cost-of-installation, cost-of-hardware and mostly, the total weight of the plane. I'd imagine savings are pretty good if you can have less computer units in the plane, run all communication through a shared bus (less heavy cabling) and use system isolation on the protocol level. The urge to do so must be really irresistible.... If only someone manages to convince the regulators and auditors that it is safe... remember, there is the truckload of money for every single plane sold to be made in the savings... boom.